In recent years, camera devices such as video cameras are used for various purposes. For example, they are used at home and at business especially for monitoring purpose and for recording and observation purposes at a production site. And the installation place of the camera devices used for the above purpose has places where people are unable to approach such as high place or narrow place or a place human body is adversely affected. Therefore, once the camera device installed, maintenance free is desirable. On the other hand, in places described above, dust, mist are scattered, and it is necessary to protect the camera device with dust proof camera housing from dust and mist.
Therefore, as a conventional dust proof camera housing, for example, an opening is provided in front of a camera lens and an air ejection port is provided in a wall of a camera housing at a position behind a camera, and air ejected from the air ejection port is ejected from the opening to the outside of the camera housing, thereby preventing dust and the like from adhering to the camera lens (Patent document 1).
Further, another one is also known which is consisted of a camera housing provided with a transparent partition plate in front of a camera lens, and an air passage formed in front of the partition plate which is directed along the wall surface of the partition plate toward the center of the partition plate from the periphery, and an air passage configured so as to blow off dust which is coming toward the partition plate, and air from an air supply to the air passages (Patent document 2).
Furthermore, another one is also known which is consisted of a transparent partition plate in front of a camera lens, and dust and mist adhering to the front surface of the transparent plate is wiped by a device such as a wiper (Patent document 3).